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<FONT color="green">001</FONT>    /*<a name="line.1"></a>
<FONT color="green">002</FONT>     * Licensed to the Apache Software Foundation (ASF) under one or more<a name="line.2"></a>
<FONT color="green">003</FONT>     * contributor license agreements.  See the NOTICE file distributed with<a name="line.3"></a>
<FONT color="green">004</FONT>     * this work for additional information regarding copyright ownership.<a name="line.4"></a>
<FONT color="green">005</FONT>     * The ASF licenses this file to You under the Apache License, Version 2.0<a name="line.5"></a>
<FONT color="green">006</FONT>     * (the "License"); you may not use this file except in compliance with<a name="line.6"></a>
<FONT color="green">007</FONT>     * the License.  You may obtain a copy of the License at<a name="line.7"></a>
<FONT color="green">008</FONT>     *<a name="line.8"></a>
<FONT color="green">009</FONT>     *      http://www.apache.org/licenses/LICENSE-2.0<a name="line.9"></a>
<FONT color="green">010</FONT>     *<a name="line.10"></a>
<FONT color="green">011</FONT>     * Unless required by applicable law or agreed to in writing, software<a name="line.11"></a>
<FONT color="green">012</FONT>     * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.12"></a>
<FONT color="green">013</FONT>     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.13"></a>
<FONT color="green">014</FONT>     * See the License for the specific language governing permissions and<a name="line.14"></a>
<FONT color="green">015</FONT>     * limitations under the License.<a name="line.15"></a>
<FONT color="green">016</FONT>     */<a name="line.16"></a>
<FONT color="green">017</FONT>    package org.apache.commons.math3.analysis;<a name="line.17"></a>
<FONT color="green">018</FONT>    <a name="line.18"></a>
<FONT color="green">019</FONT>    /**<a name="line.19"></a>
<FONT color="green">020</FONT>     * An interface representing a univariate real function.<a name="line.20"></a>
<FONT color="green">021</FONT>     * &lt;br/&gt;<a name="line.21"></a>
<FONT color="green">022</FONT>     * When a &lt;em&gt;user-defined&lt;/em&gt; function encounters an error during<a name="line.22"></a>
<FONT color="green">023</FONT>     * evaluation, the {@link #value(double) value} method should throw a<a name="line.23"></a>
<FONT color="green">024</FONT>     * &lt;em&gt;user-defined&lt;/em&gt; unchecked exception.<a name="line.24"></a>
<FONT color="green">025</FONT>     * &lt;br/&gt;<a name="line.25"></a>
<FONT color="green">026</FONT>     * The following code excerpt shows the recommended way to do that using<a name="line.26"></a>
<FONT color="green">027</FONT>     * a root solver as an example, but the same construct is applicable to<a name="line.27"></a>
<FONT color="green">028</FONT>     * ODE integrators or optimizers.<a name="line.28"></a>
<FONT color="green">029</FONT>     *<a name="line.29"></a>
<FONT color="green">030</FONT>     * &lt;pre&gt;<a name="line.30"></a>
<FONT color="green">031</FONT>     * private static class LocalException extends RuntimeException {<a name="line.31"></a>
<FONT color="green">032</FONT>     *     // The x value that caused the problem.<a name="line.32"></a>
<FONT color="green">033</FONT>     *     private final double x;<a name="line.33"></a>
<FONT color="green">034</FONT>     *<a name="line.34"></a>
<FONT color="green">035</FONT>     *     public LocalException(double x) {<a name="line.35"></a>
<FONT color="green">036</FONT>     *         this.x = x;<a name="line.36"></a>
<FONT color="green">037</FONT>     *     }<a name="line.37"></a>
<FONT color="green">038</FONT>     *<a name="line.38"></a>
<FONT color="green">039</FONT>     *     public double getX() {<a name="line.39"></a>
<FONT color="green">040</FONT>     *         return x;<a name="line.40"></a>
<FONT color="green">041</FONT>     *     }<a name="line.41"></a>
<FONT color="green">042</FONT>     * }<a name="line.42"></a>
<FONT color="green">043</FONT>     *<a name="line.43"></a>
<FONT color="green">044</FONT>     * private static class MyFunction implements UnivariateFunction {<a name="line.44"></a>
<FONT color="green">045</FONT>     *     public double value(double x) {<a name="line.45"></a>
<FONT color="green">046</FONT>     *         double y = hugeFormula(x);<a name="line.46"></a>
<FONT color="green">047</FONT>     *         if (somethingBadHappens) {<a name="line.47"></a>
<FONT color="green">048</FONT>     *           throw new LocalException(x);<a name="line.48"></a>
<FONT color="green">049</FONT>     *         }<a name="line.49"></a>
<FONT color="green">050</FONT>     *         return y;<a name="line.50"></a>
<FONT color="green">051</FONT>     *     }<a name="line.51"></a>
<FONT color="green">052</FONT>     * }<a name="line.52"></a>
<FONT color="green">053</FONT>     *<a name="line.53"></a>
<FONT color="green">054</FONT>     * public void compute() {<a name="line.54"></a>
<FONT color="green">055</FONT>     *     try {<a name="line.55"></a>
<FONT color="green">056</FONT>     *         solver.solve(maxEval, new MyFunction(a, b, c), min, max);<a name="line.56"></a>
<FONT color="green">057</FONT>     *     } catch (LocalException le) {<a name="line.57"></a>
<FONT color="green">058</FONT>     *         // Retrieve the x value.<a name="line.58"></a>
<FONT color="green">059</FONT>     *     }<a name="line.59"></a>
<FONT color="green">060</FONT>     * }<a name="line.60"></a>
<FONT color="green">061</FONT>     * &lt;/pre&gt;<a name="line.61"></a>
<FONT color="green">062</FONT>     *<a name="line.62"></a>
<FONT color="green">063</FONT>     * As shown, the exception is local to the user's code and it is guaranteed<a name="line.63"></a>
<FONT color="green">064</FONT>     * that Apache Commons Math will not catch it.<a name="line.64"></a>
<FONT color="green">065</FONT>     *<a name="line.65"></a>
<FONT color="green">066</FONT>     * @version $Id: UnivariateFunction.java 1364387 2012-07-22 18:14:11Z tn $<a name="line.66"></a>
<FONT color="green">067</FONT>     */<a name="line.67"></a>
<FONT color="green">068</FONT>    public interface UnivariateFunction {<a name="line.68"></a>
<FONT color="green">069</FONT>        /**<a name="line.69"></a>
<FONT color="green">070</FONT>         * Compute the value of the function.<a name="line.70"></a>
<FONT color="green">071</FONT>         *<a name="line.71"></a>
<FONT color="green">072</FONT>         * @param x Point at which the function value should be computed.<a name="line.72"></a>
<FONT color="green">073</FONT>         * @return the value of the function.<a name="line.73"></a>
<FONT color="green">074</FONT>         * @throws IllegalArgumentException when the activated method itself can<a name="line.74"></a>
<FONT color="green">075</FONT>         * ascertain that a precondition, specified in the API expressed at the<a name="line.75"></a>
<FONT color="green">076</FONT>         * level of the activated method, has been violated.<a name="line.76"></a>
<FONT color="green">077</FONT>         * When Commons Math throws an {@code IllegalArgumentException}, it is<a name="line.77"></a>
<FONT color="green">078</FONT>         * usually the consequence of checking the actual parameters passed to<a name="line.78"></a>
<FONT color="green">079</FONT>         * the method.<a name="line.79"></a>
<FONT color="green">080</FONT>         */<a name="line.80"></a>
<FONT color="green">081</FONT>        double value(double x);<a name="line.81"></a>
<FONT color="green">082</FONT>    }<a name="line.82"></a>




























































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